Bill,
I bought the ivory TT line last year and posted the very same question. Some said "do it" some said "no way, you'll ruin the line." Well, I took a chance and dyed it olive (Rit colors sunshine yellow & dark green mixed, doesn't take much green to turn the yellow olive). I prepared the dye according to the stove top directions. However, I boiled less water than stated about 2 gallons so I could later add cold water to cool down the dye bath down quite a bit so it wasn't too hot. I'm pretty sure boiling water would ruin the line.

I coiled the line loose and used a trash bag tie, loosely twisted around the line. Only had it in the dye bath for about 30 seconds...WORKS QUICK, rinsed in cold water and it worked great.

I've been fishing with the line for a the last year with no problems.